immigration. some say this is a chance to touch home the new message. >> throw away the rhetoric, the language that turns people off, and talk about it in a real leadership way. >> as night falls, the intense preparations are at an end. they will soon face each other for a debate but some say will shake up the race for the white house. >> so, how significant is tonight's debate? i am joined by the national editor of "a vanity fair" magazine. thank you very much. obviously, these debates have been analyzed for their significance. given the context of this election, how significant is tonight? >> it could be significant. the balance of the evidence suggests that the challenger has to gain in the first debate. he has the most -- obviously, mitt romney has the most to gain. he also has the most to lose.